1. Field of the Invention
The invention relates generally to a method of manufacturing a capacitor in a semiconductor device. More particularly, the invention relates to a method of manufacturing a capacitor in a semiconductor device, wherein a metal is used as an upper electrode and a lower electrode, and a dielectric film is formed in a double structure of a titanium-containing tantalum oxide film and an amorphous tantalum oxide film, thus securing a sufficient capacitance while improving an electrical characteristic of the application.
2. Description of the Prior Art
As a semiconductor device is more highly integrated, the cell size of a capacitor is increasingly reduced, although the capacitance per cell necessary for a stable operation of a device is not changed. A capacitor using a tantalum oxide (Ta.sub.2 O.sub.5) film, which has been developed as a dielectric film, and a polysilicon film as a lower electrode could not secure a sufficient capacitance.
In order to solve this problem, the lower electrode must be formed of a metal layer to lower the effective thickness or to secure its capacitance, or a material having a high dielectric constant than a tantalum oxide film (.di-elect cons.=25) must be used.